Dunnage bag

ABSTRACT

AN INFLATABLE AND DISPOSABLE DUNNAGE BAG HAVING AN AIR-TIGHT BLADDER ENCLOSED IN A MULTI-PLY CONTAINER FOLDED ALONG PARALLEL FOLD LINES SO THAT THE BAG, WHEN NOT INFLATED, IS FLAT WITH A BACK AND FRONT WALL, THE PLIES IN THE FRONT WALL OF THE MULTI-PLY CONTAINER AND THE PLIES IN THE BACK WALL BEING JOINED TO EACH OTHER BY FLAPS EXTENDING FROM THE END OF THE PLIES IN ONE OF THE WALLS AND BEYOND THE END OF THE PLIES IN THE OTHER OF THE WALLS AND BEING FOLDED OVER THE END OF (CONTAINER) CONTAINER AND THE   AIRTIGHT BLADDER AND SECURED TO THE PLIES IN THE OTHER OF THE CONTAINER WALLS.

C. F. EVANS Oct. 16, 1973 DUNNAGE BAG 2 Sheets-Sheet 1 Original FiledMarch 13, 1968 Oct. 16, 1973 c. F. EVANS Re. 27,787

DUNNAUU. [BAG Original Film1 MCllCh 13, 196B .1 511001::-1111111 UnitedStates Patent O 27,787 DUNNAGE BAG Carlton F. Evans, Warwick, N.Y.,assignor to International Paper Co., New York, N.Y.

riginal No. 3,506,143, dated Apr. 14, 1970, Ser. No. 712,858, Mar. 13,1968. Application for reissue Apr. 6, 1972, Ser. No. 241,852

Int. Cl. B65g I/14 U.S. Cl. 214-105 D 9 Claims Matter enclosed in heavybrackets appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT F THE DISCLOSURE An inatable and disposable dunnage bag havingan air-tight bladder enclosed in a multi-ply container folded alongparallel fold lines so that the bag, when not inflated, is flat with aback and front wall, the plies in the front wall of the multi-plycontainer and the plies in the back wall being joined to each other byflaps extending from the end of the plies in one of the walls and beyondthe end of the plies in the other of the walls and being folded over theend of the [containr] container and the airtight bladder and secured tothe plies in the other of the container walls.

This invention relates to dunnage for use in shipment of freight byrail, ship, truck, aircraft, and the like, and, more particularly, to adisposable dunnage bag for such use.

When transporting freight by rail, truck, aircraft, and the like, it iscustomary to till or bridge the space left between the freight or wallsof the freight carrying compartment to prevent the freight from shiftingand damaging the freight and compartment. Preventing shifting and damageto the freight and compartment are, of course, important but the time,labor and costs involving in installing filling or briding materialsbefore [shipmen'] shipment, removing such materials after shipment anddisposing of the removed filling or bridging materials has, heretofore,added substantially to shipping costs.

To reduce the time and labor of installation and removal, more recentlyinflatable dunnage bags have been used to bridge the space. The deflatedbag is inserted into the space and inflated through a valve in thecontainer wall. One such bag has been made of rubber and canvas and,because of the bag cost, is usually deflated and returned to the shipperfor reuse. In order that such bag may be reused, it must, of course, bedeflated and handled with care and must be accounted for and returned tothe shipper. This adds to the cost of this type of bag.

Attempts to make a less costly bag which, after use, could beeconomically disposed of have met with limited success. One such attempthas been to form a multiwall tube having outer Walls of kraft paper,overlapped and glued longitudinally along the tube, with a bladder inthe center of the tube of high density polyethylene, rubber or the like,and to seal the ends of the tube with rods and metal clamps. Suchclamped end tubes, although less expensive than rubber [a] and canvas,are not fully satisfactory because of the oost of the clamps. Moreover,such clamps are rigid and, unless such bag is properly positioned andhandled, the rigid clamps can damage the freight container, andadjoining bags.

In the instant invention, a disposable dunnage bag is formed byenclosing an airtight bladder of high density polyethylene, rubber, orthe like, in a multi-ply container. The multi-ply container is made upof a plurality of sheets, superimposed one over the other in thelongitudinal or ICC machine direction of the sheets. Each sheet isfolded along parallel fold lines so that the sheet is llat with a backand front wall between the fold lines and with one of its longitudinaledges overlapping the other longitudinal edge. Where the longitudinaledges of each sheet overlap, the overlapped edges are glued to form aseam extending in the longitudinal, machine direction, of the sheet.Each outer sheet is folded, and the edge overlapped and glued, after thepreceding inner sheet has been folded, lapped and glued s0 that, whenall the sheets have been folded, overlapped and glued, the sheets arenot connected to each other. When expanded, the sheets form a multi-wallor multi-ply tube with each inner sheet or ply in contact [wth] with theimmediately adjacent outer sheet so that the sheets, or plies, reinforceeach other. The sheets may be superimposed, folded, edge lapped andglued on a tubing machine, preferably, with the overlapped seamed edgesof the sheets offset with respect to each other so that the seam on oneply does not overlay the seam on the adjacent plies.

The airtight bladder which, when inflated expands, into contact i[wtih]with the inner Wall of the inner ply is supported by the multi-ply wallsof the container. A valve is attached to the bladder and extends throughthe walls of the container where it is accessible for inflating thecontainer.

In the manufacture of the dunnage bag, the bag is flat and, for shipmentand storage before use, may remain flat. The bladder, which may be aseamless tube of polyethylene, rubber or the like, cut to the desiredlength and glued or heat sealed at its opposite ends, a sheet folded atone edge and glued or heat sealed along its other three edges, or twosheets glued or heat sealed along all four edges, is inserted into thecollapsed, or flattened, multiwall container. The container is cut to alength to accommodate the bladder and the ends of the container aresealed by flaps extending from one side wall of the paper containersheets and glued to the other side wall. Preferably, when ilat, thelength and width of the container, at its inner wall are the same, orslightly smaller than, the bladder.

The invention will be understood from the following description anddrawings, in which:

FIG. 1 is a perspective view, in elevation of one end of the dunnage bagof the instant invention showing, partially broken away, the plies andflaps;

FIG. 2 is a cross-sectional view taken along line 2 2 of FIG. 1;

FIG. 3 is a perspective view of the bladder of the bag of FIG. l; and

FIG. 4 is a side view of the bag of FIG. l showing the bag in place andinflated between the ends of paper rolls for shipment of the rolls.

Referring to FIGS. l, 2 and 3 the bladder, generally designated 2, iscut to the desired length from a tube of air impervious material, suchas polyethylene, and heat sealed, or glued, at its opposite ends alonglines 4, 6. Hole 8, for receiving the end of valve 10, is cut in onewall of bladder 2 and valve 10 is attached and clamped, glued, or heatsealed to bladder 2, forming an airtight connection between valve 10 andthe wall of bladder 2. Thus, when inflated through valve 10, ashereinafter described, bladder 2 expands and the air introduced into thebladder through valve 10 is entrapped and remains sealed in bladder 2until valve 10 is opened or bladder 2 is torn or ruptured.

Bladder 2 is encased, or enveloped, in a multi-ply container rnacle upby a plurality of sheets 12, 14, 16, 18, 20 and 22 superimposed, oneover the other, and folded so that longitudinal edges of each sheetoverlap and the overlapped edges of each sheet are adhesively secured toform a longitudinal seam. Preferably, the sheets are folded and thelongitudinal edges are overlapped and secured on a tubing machine withthe overlapped seamed edges of the sheets staggered longitudinally ofthe tube with the seam of one tube offset relative to the seams of theadjacent tubes. In folding, lapping and securing the edges on a tubingmachine, the multi-ply tube, formed in the preferred embodiment with sixpaper sheets or plies, is a continuous flattened tube from which thecontainers are cut in suitable length.

The width of the outer edge of flattened bladder 2 and each of the plies12, 14, 16, 18, 20 and 22 is the same as, or slightly wider than, thewidth of the inner diameter of the next outer ply member. This is ofsubstantial importance because, when inated, the bladder does notstretch, is not weakened and is fully supported by the plies of thecontainer.

When closed, the inner wall of the multi-ply container, at the oppositeends of bladder 2, is slightly shorter than the seal of bladder 2 sothat the sealed ends 4, 6, at the ends of bladder 2 bear against the endof the multi-ply container or bladder 2 at the pressure side of sealedend 4, 6 bear on the end of the container. Thus, at its ends, bladder 2is not stretched or weakened when the dunnage bag of the instantinvention is inflated. Except for valve 10, which projects outwardlythrough the plies of the container, bladder 2, although containedwithin, is free of any connection to the container.

Referring to FIGS. 1 and 2, the plies at one wall of the flattenedcontainer are cut flush with, or slightly short of, the seal of bladder2 and the plies at the opposite wall are cut at a distance beyond theend of bladder 2 to thereby form flaps. In closing the end of thecontainer, an adhesive coating, such as polyethylene, a hot melt orpressure sensitive adhesive, is applied to the flap of each ply and theflap is folded over the open end and, with the adhesive, is secured tothe ply at the opposite wall. Not all of the plies need be adhesivelysecured but, in order that the container have sufficient strength at itsends to withstand impact forced, at least three, and preferably four, ofthe aps in a 6-ply container are adhesively secured. For example, incarrying out the invention, the flap or inner sheet 12 may be foldedand, without adhesive, inserted into the end of inner ply 12 on theinner side of ply 12 of the flattened container at the opposite wall.The flap of sheet 14, with adhesive, is then adhesively secured t theouter side of sheet 12 at the opposite wall of the flat container.Adhesive is next applied to the flap of sheet 16 and the flap of sheet16 and the flap of sheet 18, without adhesive, are then folded and laidover the end of sheet 16 at the opposite wall of the flattened containerand the flap of sheet 16 is adhesively secured to the outer side ofsheet 16. Adhesive is next applied to the flap of sheet 20, the flap isfolded and adhesively secured to the outer side of sheet 20 at theopposite wall of the flattened container. Finally, adhesive is appliedto the flap of sheet 22 and the flap is folded and adhesively secured tothe outer side of sheet 22. The flaps at the opposite end of thecontainer are folded and adhesively secured in the same manner.

Referring now to FIG. 4, showing an inflated dunnage bag of the instantinvention in place between the ends of paper rolls for shipment to therolls, the bag of the instant invention, generally designated 52, ispositioned between the ends of paper rolls 54, 56 in container 58 whichmay be a freight car, ship, truck or aircraft. Because paper rolls 54,56 are round, the rolls are held from rolling by chocks 60, 62. Rolls54, 56 may be rolled into place or placed in compartment 58 with a lifttruck or other suitable handling equipment. Dunnage bag S2, which isdeflated and flat, is inserted between the facing ends of rolls 54, 56and, through valve 10, bag 52 is inflated to a pressure of about 8 lbs.p.s.i. to set the load. After the load is set dunnage bag 52 [in] isdeflated, through valve 10, to a pressure of from about 2 to 4 lbs.p.s.i. for shipment. By first inllating the bag to a higher pressure toset the load and, thereafter, deflating the bag to a lower pressure, thefreight to be held by the inflated bag during shipment is moved intoabutment with the container walls or other items of freight beingshipped.

When the freight reaches its destination, the inflated bag 52 may beripped open with a knife, freight hook or similar tool and, when rippedopen, the bag rapidly deflates. The deflated bag can then be removed anddisposed of, such as, by burning. Rapid deflation of the bag by tearingor ripping of the container avoids delays in unloading of the freight.

The strength of the bag of the instant invention will, of course, dependupon the strength and quality of the material in the plies of themulti-ply container. For most purposes for which the dunnage bag of theinstant invention is intended, it is preferred to make the containerfrom lb. kraft paper sheets, with the outer sheet or ply coated with,for example, polyethylene, for weather and wear resistance. Thecontainer may, however, be made from other sheet materials, such asplastic sheets with or without reinforcement. Preferably, waterresistant adhesives are employed in the manufacture of the bag.

The terms and expressions which have been employed are used as terms ofdescription and not of limitation, and there is no intention in the useof such terms and expressions of excluding any equivalents of thefeatures shown and described or portions thereof, but it is recognizedthat various modifications are possible.

What is claimed is:

1. An inflatable dunnage bag comprising a multi-ply container made up ofa plurality of sheets superimposed one over the other and folded alongparallel fold lines so that the sheets are flat between the fold linesforming back and front container walls between the fold lines and withone of the longitudinal edges of each sheet overlapped with, andadhesively secured to, the other longitudinal edge, an air-tight bladdersealed at its opposite ends in said container, a valve in the wall ofsaid bladder for inllating said bladder, said valve extending outwardlythrough one of said walls of said multi-ply container, the plies of oneof said container walls, at the end of said bag, extending beyond theend of the plies of the other wall and forming flaps, the flap on theinnermost ply immediately adjacent to said bladder being folded over theend of said bladder and tucked into the open end of said innermost plybetween said bladder and the inner surface of the other wall of saidinnermost ply for frictional engagement with said inner surface as saidbladder is inflated and for supporting the sealed end of said bladder atthe pressure side of said seal when said bladder is inflated, the flapon the ply immediately adjacent to said innermost ply being folded overthe end of said bladder and said flap on the innermost ply and tuckedinto the open end of said immediately adjacent ply and adhesivelysecured to the outer surface of said other wall of said innermost ply,the flap on the outermost ply being folded over the end of said bladderand the flaps on the inner plies and being adhesively secured to theouter surface of the outer wall of said outermost ply.

2. An inflatable dunnage bag, as recited in claim 1 in which said sheetsare 100 pound kraft paper sheet and the outer sheet of said container iscoated with polyethylene.

3. An inflatable dunnage bag, as recited in claim 2, in which said`bladder is a polyethylene tube heat sealed at its opposite ends.

4. An inflatable dunnage bag, as recited in claim l, in which certain ofthe flaps on the plies intermediate said ply adjacent to said innermostply and said outermost ply are folded over the end of said bladder andthe flaps on the plies inner thereto and tucked into the open end of theopposite ply wall between the inner wall of said opposite ply wall andthe outer wall of the adjacent inner ply for frictional engagement withsaid inner wall of said opposite ply wall when said bladder is inflated.

5. An inatable dunnage bag, as recited in claim 4, in which certain ofthe aps on said intermediate plies are folded over the end of saidbladder and the aps on the plies inner thereto and adhesively secured tothe outer surface of the opposite ply wall.

6. An inflatable dunnage bag comprising a multi-ply container made up ofan inner sheet, an outer sheet and a plurality of intermediate sheetssuperimposed one over the other and folded along parallel fold lines sothat the sheets are flat between the fold lines forming back and frontcontainer walls between the fold lines and with one of the longitudinaledges of each sheet overlapped with, and adhesively secured t0, theother longitudinal edge, an airtight bladder sealed at its opposite endsin said container, and a valve in the wall of said bladder for inflatingsaid bladder, said valve extending outwardly through one of said wallsof said multi-ply container, the plies of one of said container walls,at the end of said bag, extending beyond the end of the plies of theother wall and forming flaps, the flap on the innermost ply immediatelyadjacent to said bladder being folded over the end of said bladder andtucked into the open end of said innermost ply between said bladder andthe inner surface of the other wall of said innermost ply for frictionalengagement with said inner surface as said bladder is infiated and forsupporting the sealed end of said bladder at the pressure side of saidseal when said bladder is inflated, the flap on the ply immediatelyadjacent to said innermost ply being folded over the end 0f said bladderand said flap on the innermost ply and being tucked into the open endbetween an adjacent pair of said plies and being adhesively secured toone surface of one wall of one of said pair of plies, the flap on theoutermost ply being folded over the end of said bladder and the flaps onthe inner plies and being adhesively secured to the outer surface of theother wall of said outermost ply.

7. An inflatable dunnage bag comprising a multi-ply container made up ofan inner sheet, an outer sheet and a plurality of intermediate sheetssuperimposed one over the other and folded along parallel fold lines sothat the sheets are flat between the fold lines forming back and frontcontainer walls between the fold lines and with one of the longitudinaledges of each sheet overlapped with, and adhesively secured to, theother longitudinal edge, an airtight bladder sealed at its opposite endsin said container, a valve in the wall of said bladder for inflatingsaid bladder, said valve extending outwardly through one of said wallsof said multi-ply container, the plies of one of said container walls,at the end of said bug, extending beyond the end of the plies of theother wall and forming flaps, the flap on the innermost ply immediatelyadjacent to said bladder being folded over the end of said bladder andtucked into the open end of said innermost ply between said bladder andthe inner surface of the other wall of said innermost ply for frictionalengagement with said inner surface as said bladder is inated and forsupporting the sealed end of said bladder at the pressure side of saidseal when said bladder is inflated, the flap on an intermediate plybeing folded over the end of said bladder and the flaps on the pliesinnert thereto and being tucked into the open end between an adjacentpair of said plies and being adhesively secured to one surface of onewall of one of said pair of plies, the flap on the outermost ply beingfolded over the end of said bladder and the flaps on the inner plies andbeing adhesively secured to a surface of the other wall of saidoutermost ply.

8. An inflatable dunnage bag comprising a multiply container made up ofan inner sheet, an outer sheet and a plurality of intermediate sheetssuperimposed one over the other and folded along parallel fold lines sothat the sheets are flat between the fold lines forming back and frontcontainer walls between the fold lines and with one of the longitudinaledges of each slzeet overlapped with, and adhesvely secured to, theother longitudinal edge, an airtight bladder sealed at its opposite endsin said container, and a valve in the wall of said bladder for inflatingsaid bladder, said valve extending outwardly through one of said wallsof said multi-ply container, the plies of one of said container walls,at the end of said bag, extending beyond the end of the plies of theother wall and forming flaps, the flap on the innermost ply immediatelyadjacent to said bladder being folded over the end of said bladder andtucked into the open end of said innermost ply between said bladder andthe inner surface of the other wall of said innermost ply for supportingthe sealed end of said bladder at the pressure side of said seal whensaid bladder is inflated, the flaps on the plies intermediate saidinnermost ply and the outermost ply each being folded over the end ofsaid bladder and the flaps on the plies inner thereto and being tuckedinto the open end of the opposite ply wall between an adjacent pair ofsaid plies, some but not all of said flaps on the plies located inwardlyof the outermost ply being adhesively secured to a respective surface ofone wall of the opposite ply wall, the remainder of said flaps on saidinwardly located plies being in frictional engagement with the wall ofthe opposite ply wall when said bladder is inflated, the flap on theoutermost ply being folded over the end of said bladder and the flaps onthe inwardly located plies and being adhesively secured to the outersurface of the other wall of said outermost ply.

9. An inflatable dunnage bag, as recited in claim 8, in which there areprovided at least four of said interi mediate sheets and in which saidflaps on at least two but not more than three of said intermediate flapsare adhesively secured to a respective surface of one wall of said pairof plies.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

UNITED STATES PATENTS 3,072,270 1/1963 Tolby et al 214-105 D 3,199,6898/ 1965 Feldkamp 10S-369 BA X 3,365,116 1/1968 Ludlow 229-55 2,075,1663/1937 Brady 229-55 3,243,822 4/1966 Lipkin 10S-369 X FOREIGN PATENTS651,509 2/ 1929 France.

ROBERT G. SHERIDAN, Primary Examiner F. E. WERNER, Assistant Examiner

